SOP

Same Origin Policies

There are already many great resources on this. Below are two short PDFs on the topic and a Mozilla Docs link for indepth reading. This is an important concept for corss-site attacks.

Mozilla Docs: https://developer.mozilla.org/en-US/docs/Web/Security/Same-origin_policy

SOP Overview(Berkeley):

https://inst.eecs.berkeley.edu/~cs261/fa17/scribe/web-security-1.pdfinst.eecs.berkeley.edu

SOP in depth(Stanford):